Lamp holder



G. B. THOMAS LAMP HOLDER Aug. 119, 192% Filed April 27, 1918 PatentedAug. 19, 1924.

UNITED STATES 1,505,821 PATENT OFFICE- GEORGE B. THOMAS, OE BRIDGEPO'RT,CONNECTICUT, ASSI GNO-R TO BRYANT ELECTRIC COMPANY, A CORPORATION OFCONNECTICUT.

LAMP HOLDER.

Application filed April 27, 1918. Serial No. 231,113.

To all whom it may concern:

Be it known that I, GEORGE B. THOMAS, a citizen of the United States ofAmerica, residing at Bridgeport, in the county of Fair-' field and Stateof Connecticut, have invented a certain new. and useful Improvement in aLamp Holder, of which the followin is a specification.

y invention relates to a lamp holder for sockets of the Edi-Swan type,and particularly to a device for steadying the lamp in its socket, theobject of my invention being to provide a simple and readily operateddevice y which the lamp may be prevented from 1 rocking on the arms ofits customary holding pins.

In the accompanying drawing, Fig. 1 is a broken side elevation of a lampsocket of the Edi-Swan type, showing a 2 lamp in position therein andengaged by the holding device to which the invention relates;

Fig. 2 is a partial side elevation thereof;

Fig. 3 is a broken side elevation showing the holding ring in theposition which it assumes on the insertion of a lamp into the socket;

Fig. 4 is a section on the line 4-4, Fig. 2;

Fig. 5 is a drop perspective of the shade holiding ring and thelamp-holding ring;

Fig. 6 is a plan of the lamp base.

Lamps of the Edi-Swan type comprise a base having a metal shell 10, towhich the the studs 12, by means of which the lamp is held in a socket.At theentering end of the shell 10 is secured an insulating button 13,carrying the lamp-terminals 14 and 15, with which cooperate thecorresponding terminals of the socket. The socket here shown forcooperating with a lamp of this type, has a casing of the same generalconstruction as that shown in my prior Patent 1,239,317 and comprises acap 16 latched to the shell 17 the other end of which is extended by asleeve 18 having a flange 19 which overlies the inturned lower edge 20of the shell 17 and rigidly secured in position by the lock nut 21,which screws upon the threaded area 22 of the sleeve and *may beutilized to hold lamp shade, as indicated in my prior patent abovereferred to. At its outer end, the

sleeve 18 is of slightly reduced diameter to 55 more closely fittelescopically over the enterglobe 11 is sealed and from which projecting end of the shell 10 of the lamp base, and is provided on oppositesides with bayonet slots, 23, with which the studs 12 of the lamp baseengage. The spring stud terminals 24 and 2 5. (Fig. 4) of the socket,which cooperate with the terminals 14 and 15 of the lamp base, arecarried by the insulating body 26 of the socket and project into thechamber formed by the sleeve 18. While there is a general correspondencebetween the diameter of the entering end of the lamp base 10 and theinternal diameter of the sleeve 18 at its outer end, there isnevertheless considerable play between these parts, with the result thatthe lamp rocks on the studs 12 after the lamp is in position. This notonly augments the flicker of the light emitted by the lamp when. thelatter is subject to vibration, but is apt to cause injury to the lampfilament and thus shorten the life of the lamp, and, furthermore, addsto the insecurity of the bayonet slot fastening. To avoid this detect, 1have now provided means carried by the lamp socket and engaging the lampin its inserted position to hold the latter rigid and prevent itsrocking on the axis of its studs 12.

This lamp-holding device in the form here shown comprises a ring 27,internally threaded at'28 to screw upon the threaded area 22 of thesocket'sleeve 18. At the opposite end of the ring a neck 29 is formed byinwardly offsetting the wall of the ring a suflicient distance toconform the internal diameter of the neck 29 substantially to that ofthe entering end of the shell 10, so that when the ring is screwedoutward on the sleeve 18, the neck 29 of the sleeve engages the shoulder30 of the lamp base. At opposite points, slots 31 are cut in the neckend of the holding ring 27 to permit the passage of the studs 12 on thelamp base into the bayonet slots 23 in .the sleeve 18,

studs 12, which, in inserted position, project through the bayonet slots23 beyond the outer face of the sleeve. This clearance between theholding ring 27 and the sleeve 18 permits the ring to be rotated afterthe lamp has been inserted in the socket. A knurled area 33 may beformed on the ring to facilitate its rotation.

The operation of this device is readily understood. In order to permitthe insertion of the lamp in the socket, the holding ring 27 is screweddown toward the socket shell 17 to get it out of obstructing position.

When turned sufficiently far down, it is neck 29 bears firmly againstthe shoulder 30 of the lamp base 10. In this position it not only holdsthe lamp against oscillation on the studs 12, but also locks the studsin engagement with the oiiset branch of the bayonet slot 23 and preventsany possibility of the lamps accidental escape from the socket.

Various modifications in detail of construction and arrangement willreadily occur to those skilled in the art which do not depart from whatI claim as my invention. I do not limit the application of this lockingdevice to sockets of-the particular construction shown, since .it mayobviously be used with any type of socket having the necessary threadedarea or equivalent means for engagement with the locking ring.

I claim 1. A lamp socket having a casing element slotted to afford abayonet joint connection with a cooperating lamp and having a threadedarea, in combination with a screw ring threaded on said area and movableinto engagement with a shouldered lamp base after the establishment ofsaid bayonet joint connection to hold the lamp against vibration withrelation to the socket, said ring surrounding the bayonet joint butbeing spaced from said casing element at the bayonet joint to clear oneof the bayonet oint members and permit the rotation of ,the ring aroundsaid joint, but constricted at its outer end to afford an end engagementwith the lamp base.

2. A lamp socket having a casing element slotted to afford a bayonet.joint connection with a cooperating lamp and having a threaded area, incombination with a screw ring threaded on said area and movable into endengagement with a shouldered lamp base after the establishment of saidbayonet joint connection to hold the lamp against vibration withrelation to the socket, said ring surrounding the bayonet joint, andbeing inwardly offset and slotted at its lamp engaging end to permit thepassage therethrough of the bayonet joint member on the lamp end.

3. The combination with an electric lamp having a shouldered base'withlateral securing studs, of an electric lamp socket having alamp-supporting casing element comprising a threaded sleevebayonet-slotted at its lamp-receiving end to accommodate said studs, andwithin which the end of the lam is socketed in inserted position,together with a shouldered ring screwed on said sleeve .andradiallyslotted to accommodate the studs on the lam base, but free torotate on 'said casing e ement when the lamp is in inserted position,the outer end of said sleeve being of reduced diameter and havin an endengagement with the shoulder oi thelamp base when said ring is movedinto lamp-engaging position.

4. In a construction as specified in claim 3, radial slots in thelamp-engaging ring extending into the shouldered area of said 1%testimony whereof I have signed my name to this s ecification.

EORGE B. THOMAS.

